In general, exciter and armature windings are connected in series in series-wound motors, which are also called series motors. Exciter current and armature current and thus also the magnetic fields caused thereby thus change their direction synchronously, so that a feed using alternating current is possible in fixed rotational direction. The exciter winding is typically low-resistance, in contrast to the shunt-wound motor. The speed of series-wound motors is strongly load-dependent. If the output torque drops, e.g., in case of idle, the speed of the armature rises because of the low current and the field attenuation accompanying it. This can continue until the motor “runs away”, which means that the speed rises ever further and can result in destruction of the motor because of the resulting centrifugal forces. Therefore, series-wound motors are generally operated using a base load, such as motor fans, gears, or a load resistor connected in parallel to the armature, to counteract a field attenuation of the exciter magnetic field. Two approaches for preventing a series-wound motor from running away can include: on the one hand an artificial increase of the mechanical load, for example, by gears or mechanical fans, on the other hand by electrically connecting a load resistor in parallel to the armature winding, so that the exciter coil also has current flowing through it in the event of decreasing armature current to maintain the exciter magnetic field. A type of hybrid motor is provided by circuitry, which connects the properties of a series-wound and a shunt-wound motor with one another.